NIH Rare Diseases:41 Usher syndrome is a genetic condition characterized by hearing loss or deafness, and progressive vision loss due to retinitis pigmentosa. three major types of usher syndrome have been described - types i, ii, and iii. the different types are distinguished by their severity and the age when signs and symptoms appear. all three types are inherited in an autosomal recessive manner, which means both copies of the disease-causing gene in each cell have mutations.
last updated: 3/3/2014